Lesson 1: ‘Is it really from a quarry?’ Prior Knowledge / Work: To put this unit in context, the children should have learnt a bit about the quarrying industry and how some materials are quarried. This information can be obtained with the use of the ‘Virtual Quarry’.
To appreciate the vast amount of uses there are of quarried materials
To carry out a simple audit of objects / products in home or school that use quarried materials
To understand why ‘rocks’ are commonly used in toothpaste
To compare the ingredients in a range of commercial toothpastes
Science –Materials, rocks and investigational work
Background Information: From the minute we wake up in the morning and carry out our normal routines of washing our face, brushing our teeth, eating our breakfast with a glass of juice, looking out of the window, we are using materials made from minerals (minerals can be defined as naturally occurring substances that are neither animal or vegetable).
Everything from the bowl you eat your cereal in, the glass your juice was in, to the radio, fridge, light bulbs and window are all there because of minerals and these minerals are extracted from the rocks that are mined from Earth.
In agriculture, construction, transportation, electronics…… in fact, just about every aspect of our lives depends in some way on the materials that we remove from the ground.
This could be seen to start from our requirement for food. Fertilisers made from potash, phosphate rock, sulphur and nitrogen are used to help crops grow. Metals used in tractors and farm equipment harvest that food. Food is transported in vehicles that are made out of metal and we even store our food in metal cans and other containers made from or with minerals. We also need mineral nutrients to keep us healthy! Our foods contain calcium, iron, magnesium, copper and zinc to name but a few – some of us even take vitamin mineral supplements to make sure we get enough!
Just about all the materials we use for construction are made from materials from the ground – brick, stone, asphalt, concrete, pipes, wires, and glass…. The list is endless!
(based on information from U.S Bureau of Mines, Office of Public Information 1992)
In an everyday house, there are numerous examples in bathrooms in particular. Just have a look at the ingredients in shampoo, cosmetics and toothpaste and it may surprise you! Many of these products contain mineral materials;
Talc – (A magnesium silicate mineral) Obviously used in talcum powder, but also found in eye shadow, some deodorants, lotions and creams.
Kaolin – (A clay) is used to absorb moisture and is used in ‘mud packs’.
Titanium dioxide – Found in make-ups, nail polish, lipstick and also in the ‘M’ on M&M sweets!
Other examples can be found on the site:
www.resourcescommittee.home.gov/emr/usgsweb/examples One of the most surprising is that every time we brush our teeth, we are using a substance that relies on quarried rocks!
When toothpaste was first developed, its function was just to clean the teeth and it was a pretty basic. Now, toothpastes help prevent gum disease and tooth decay. Some whiten teeth and others stop teeth feeling sensitive.
Toothpastes are made up of many different ingredients (just have a look at the ingredient list on yours!). Flouride is one of the most important as it was found to help prevent tooth decay. One of the main sources of fluoride is fluorspar. Fluorspar is a mineral made up of calcium and fluorine. Fluorspar ore is found all over the world, but China is the world’s largest producer. Also, toothpaste needs to be the right consistency and needs to remain as a ‘paste’, rather than drying out. Glycerin is often used to achieve this. Toothpastes need a material to act as an abrasive. These help the toothpaste to remove plaque. Many different minerals are used in different types of toothpaste. The most common are sodium bicarbonate and calcium bicarbonate. Sodium bicarbonate also has whitening properties.
(based on ‘Rocks in your Mouth’ by John Sznopek, USGS)
Activity: Use the background information and the suggested website to introduce the children to the vast impact that quarried materials have on our lives. Discuss some of these materials with the children. Have a selection of everyday products such as cosmetics, vitamins, toothpaste etc. that you can look at the ingredients of and try and find those that have a mineral content.
Set the children the task of investigating this further at home. Ask them to find five products at home where they think the ingredients contain minerals. Get them to bring the product in, or copy down the ingredients.
Make a collection of several different brands of toothpaste. Allow the children to compare the different ingredients in these toothpastes. Are some appearing in all toothpastes? You may also carry out a simple survey within the class to find out which toothpaste brands are most commonly used and why? What influences their choice of toothpaste? (most will say taste!) Also discuss with the children what adverts there are around at present advertising toothpastes and what persuasive techniques do they use to try and get you to buy that product.
Reading the information on a variety of toothpaste packets can also prove interesting. Do these texts make claims, provide information, use statistics (some use graphs to show plaque build up), use diagrams, instructions, slogans……. It is amazing how much the manufacturers cram on a small packet, but how many of us actually read all of this?!